Investigation of a new high energy battery system for transcutaneous transmission of energy e.g. in a Ventricular Assist System (VAS) or other heart pumps is proposed. The development is based on the stabilized nickel-zinc battery system developed by Electrochimica Corp. which offers the following advantages: a) an energy density twice that of present nickel-cadmium cells b) a long cycle life c) A higher cell voltage resulting in fewer cells for a battery of a given voltage Up to now the nickel-zinc has been available only in vented cell forms. Sealed batteries are a necessity for the internal power source of a VAS and they are also desirable for the external units. As a key approach towards sealing of nickel-zinc cells an oxygen recombination technique is proposed which would permit considerable latitude in charging and overcharging without developing any significant pressures in the battery. A four task six mo (Phase I) program is presented, to develop this technique and establish a basic approach towards cel design for future hardware development later in Phase II for device applications.